/*
 * Copyright ConsenSys AG.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 *
 * SPDX-License-Identifier: Apache-2.0
 */
package org.hyperledger.besu.plugin.services.storage;

import java.io.Closeable;
import org.hyperledger.besu.plugin.Unstable;
import org.hyperledger.besu.plugin.services.BesuConfiguration;
import org.hyperledger.besu.plugin.services.MetricsSystem;
import org.hyperledger.besu.plugin.services.exception.StorageException;

/** Factory for creating key-value storage instances. */
@Unstable
public interface KeyValueStorageFactory extends Closeable {

    /**
     * Retrieves the identity of the key-value storage factory.
     *
     * @return the storage identifier, used when selecting the appropriate storage service.
     */
    String getName();

    /**
     * Creates a new key-value storage instance, appropriate for the given segment.
     *
     * <p>When segment isolation is not supported, the create will still be called with each of the
     * required segments, where the same storage instance should be returned.
     *
     * <p>New segments may be introduced in future releases and should result in a new empty
     * key-space. Segments created with the identifier of an existing segment should have the same
     * data as that existing segment.
     *
     * @param segment identity of the isolation segment, an identifier for the data set the storage
     *     will contain.
     * @param configuration common configuration available to plugins, in a populated state.
     * @param metricsSystem metrics component for recording key-value storage events.
     * @return the storage instance reserved for the given segment.
     * @exception StorageException problem encountered when creating storage for the segment.
     */
    KeyValueStorage create(
            SegmentIdentifier segment, BesuConfiguration configuration, MetricsSystem metricsSystem)
            throws StorageException;

    /**
     * Whether storage segment isolation is supported by the factory created instances.
     *
     * <p>As supporting segment isolation is similar to a separating keys into distinct namespaces,
     * where operations only affect within that segment i.e. the same key from two segments point to
     * separate values.
     *
     * @return <code>true</code> when the created storage instances are isolated from each other,
     *     <code>false</code> when keys of different segments can collide with each other.
     */
    boolean isSegmentIsolationSupported();
}
